This invention relates to injection molding, and in particular, to a method of using a multi-purpose processing apparatus or tool for simultaneously performing the multiple functions of forming, cutting, and molding, such as in the process of in-mold decorating.
Typically, a part that requires in-mold decorating may first require multiple steps to be performed. The first step may be to print the part in web form. The web form may then be fed through a web cutting apparatus, which reads a registration mark, thereby cutting the web into sheets or parts at desired locations. The part, in printed and cut form, may be sent to a station where locations are punched. After the punching operation is complete, the part is ready and able to be sent to the former, where it may be hand fed and formed. The formed sheet may then be sent to the injection molding machine, where again individual sheets are manually hand fed to be molded. Finally, the desired product is produced.
The cost of such an operation is considerable. There are the obvious costs of performing each separate operation, as well as the material handling costs between each operation. However, considerable hidden costs exist as well. Such hidden costs include coordinating all of the separate operations involved, i.e., printing, perforating and cutting the part, punching locations, sending the part to a separate station to be formed, and to another separate station to be molded, as well as labor costs, such as the numerous manual operations included therein. Further, these tasks can slow the process, creating troublesome bottlenecks. And the manual nature of these processes can raise quality concerns.
Accordingly, a need exists for a multi-purpose processing apparatus which allows an injection molding operation to proceed without the need to perform the pre-injection molding individual steps such as cutting, punching, and forming. In other words, a need exists for a device which accepts the product in web form, thereby combining pre-injection molding stations into one continuous feed apparatus, which eliminates the manual labor and expense associated with conventional in-mold decorated injection molding. Further, a need exists for a multi-purpose processing apparatus which allows the steps of forming, cutting, and molding to be performed on a printed feed roll simultaneously at different positions within the injection molding machine.
Therefore, it is an object of the present invention to provide a multi-purpose processing apparatus which allows an injection molding operation to proceed without the need to perform the pre-injection molding individual steps such as cutting, punching, and forming. It is a further object of the present invention to provide a multi-purpose processing apparatus which accepts the printed stock in web form, thereby combining pre-injection molding stations into one continuous feed apparatus, which eliminates the manual labor usually associated with injection molding. Further, it is also an object of the present invention to provide a multi-purpose processing apparatus which allows the steps of forming, cutting, and molding to be performed on a printed feed roll simultaneously at different positions within the injection molding machine.
The present invention satisfies this need by providing a multi-purpose processing apparatus able to perform both a forming operation and a cutting/injection molding operation. Using this multi-purpose apparatus in a manufacturing process eliminates the need for three separate and distinct steps of forming, cutting, and injection molding. Use of the multi-purpose apparatus results in a process which combines the three steps of forming, cutting, and injection molding into one continuous operation performed within the injection molding machine. The multi-purpose apparatus thereby eliminates the need for a punching operation before reaching the injection molding machine to position forming locations, as there is now no need to hand feed the forming operation. This tool allows the three steps of forming, cutting and molding to be performed simultaneously as parts are fed into the multi-purpose apparatus.
The present invention multi-purpose processing apparatus fits into a substantially conventional injection molding machine. The apparatus is preferably mounted on a quick change mounting plate, but may be mounted directly to both press platen surfaces of the injection molding machine. The multi-purpose apparatus has a first portion which performs the forming operation and a second portion which performs the cutting and molding operation.
The forming operation is typically done by pressure forming. The forming operation utilizes unused space within the injection molding machine, as well as clamping pressure already supplied by the injection molding machine. The injection molding operation is typical as is known in the art. For the cutting portion, the part can be pattern-cut while in the mold, preferably by cutting means in the mold cutting the substrate during closing of the mold. The cutting operation is optional, as the tool can be set up to either perform the cutting operation or not, as desired.
In use, the process begins with a roll of a flat, printed web mounted on a roll mount. The web is fed into the multi-purpose processing apparatus by a web feed system. After a portion of the web is formed, it is advanced to the cutting/molding operation within the multi-purpose tool. As the formed portion is cut and molded, a new portion is advanced to the forming operation and formed simultaneously with the portion which was just formed being cut and/or molded. The cutting/molding operation can be set up to either cut or not cut the part. If the cutting/molding operation is not set in a cutting mode, the parts, formed and molded, continue on to be rolled up onto another roll. This process can continue until a new feed roll is needed, forming multiple finished parts without having to transport them after each individual step is completed.
If the cutting/molding operation is set up to perform a cutting operation, simultaneous with the injection molding process the substrate can be pattern-cut, preferably by a cutting means on the tool. The part, now formed, cut, and molded, can generally either fall into a bin, or be picked up by a robot.
As stated earlier, in a conventional in-mold decorated injection molding operation numerous tasks and steps are involved. The present invention allows the printed web to be in roll stock form and be taken directly to the injection molding machine. Therefore, the typical steps required for an in mold decorated part before the part gets to the injection molding machine, i.e., cutting, punching, and forming, are not necessary. Separate cutting and punching operations are no longer required, and the forming operation is performed within the injection molding machine.
Also, as previously mentioned, other hidden costs in a typical process would include such things as coordinating printing, perforating and cutting the part, punching locations, sending the part to the former station to have it formed, and sending the part to the injection molding station to have it molded. With the present invention, the injection molding machine operator can merely track the inventory of printed roll stock on hand, and send notification when more is needed. All of the intermediate operations discussed are no longer required in the process, many of which are manual tasks which are typically slower and less reliable.